Development of copper nanoparticles and multi-walled carbon nanotubes modified sensor system for effective and practical detection of glyphosate

Abstract

Aqueous glyphosate (Gly) was detected voltammetrically by modifying the surface of the glassy carbon electrode with a multi-walled carbon nanotube (MWCNT), copper nanoparticles (CuNPs) and pyrrole (Py) in a one-step method. Since the Cu-Glyphosate and Cu-Pyrrole compounds adsorb on the MWCNT surface and block the progress of the redox reaction of copper, a decreasing peak current graph appears in the cyclic (CV) and differential pulse voltammetries (DPV). Pyrrole increases the sensitivity of the Gly electrochemical sensor. The electrochemical behaviour of the MWCNT/CuNP/Py/GCE sensor for Gly detection was evaluated by the CV and DPV in a PBS medium at a pH of 6. Under the optimised conditions, the constructed sensor showed good linearity between 0.01-0.1 mu M (R2 = 0.9906) and 0.1-1.0 mu M (R2 = 0.9965) with a detection limit of 0.002 mu M (S/N = 3) by the DPV. The sensor was also applied to real samples such as soil, spinach, peas, carrots, and tomatoes with recoveries ranging from 97% to 104%. According to the Gly peak current signal, all ions and pesticides were examined, resulting in a relative standard deviation of less than 5% for interference studies. After four weeks of the stored samples at 25 degrees C, the current peak intensity of the platform remained at 99% of the obtained measurements, with only insignificant differences.